Exposure process for enhancing refractive index variation of chalcogenide glass film

Abstract

The invention provides an exposure process for enhancing the refractive index variation of a chalcogenide glass film, and belongs to the technical field of film optical performance regulation and control. Comprising the following steps: preparing a chalcogenide glass film on a soda-lime glass substrate; placing the thin film in a preset atmosphere environment; a laser with the wave band matched with the absorption wave band of the chalcogenide glass thin film is adopted for carrying out laser exposure treatment on the thin film, the refractive index of the thin film can be changed, and the refractive index change amount higher than that in the air atmosphere can be obtained in the oxygen-enriched atmosphere. According to the invention, the refractive index change amount of the chalcogenide glass film can be obviously enhanced only by regulating and controlling the environmental atmosphere during laser exposure.

Description

Technical Field

[0001] This invention relates to the field of thin film optical property control technology, specifically to an exposure process for enhancing the change in refractive index of chalcogenide glass thin films. Background Technology

[0002] Chalcogenide glasses, as amorphous optical materials containing chalcogen elements such as sulfur, selenium, and tellurium, possess advantages such as high linear and nonlinear refractive indices, wide infrared transmission windows, and significant photoinduced effects, making them highly promising for cutting-edge applications such as photonic chips, infrared sensing, optical storage, and tunable filters. Utilizing laser-induced photoinduced effects to modulate the refractive index of chalcogenide glass thin films has become one of the key methods for fabricating micro- and nano-photonic devices such as optical waveguides and gratings. This method offers a wide tuning range, good stability, and no carrier effects, outperforming many traditional methods.

[0003] However, common methods for enhancing refractive index changes in existing technologies, such as elemental doping or thermal annealing, have significant limitations: doping processes are complex and prone to introducing defects, while annealing processes are difficult to precisely control local properties, resulting in insufficient uniformity and stability of refractive index changes. These methods are not only cumbersome and costly, but may also affect the optical quality of the thin film, hindering the large-scale application of chalcogenide glasses in integrated photonic devices. Therefore, the industry urgently needs a simple, effective, and widely applicable enhancement method to overcome the shortcomings of existing technologies. Summary of the Invention

[0004] The purpose of this invention is to propose a method to significantly increase the refractive index change of chalcogenide glass thin films by controlling the ambient atmosphere, especially the oxygen-rich conditions, during laser exposure. This method requires no complex external processing and directly utilizes the interaction of atmosphere and photoinduced effects, solving the problems of poor stability and low controllability of traditional processes, and providing a new approach for the fabrication of high-performance photonic devices.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: an exposure process that enhances the change in refractive index of chalcogenide glass thin films.

[0006] A laser exposure process for enhancing the refractive index change of a chalcogenide glass thin film includes the following steps: preparing a chalcogenide glass thin film on a soda-lime glass substrate; placing the thin film in a preset atmosphere; and performing laser exposure treatment on the thin film using a semiconductor laser whose wavelength matches the absorption wavelength of the chalcogenide glass thin film, which can change the refractive index of the thin film and obtain a higher refractive index change than that in an oxygen-rich atmosphere than in an air atmosphere.

[0007] Preferably, the chalcogenide glass material is a Ge-Sb-Se ternary structure chalcogenide glass.

[0008] Preferably, the chalcogenide glass film is prepared by vacuum deposition technology.

[0009] Preferably, the oxygen-rich atmosphere is formed by placing the chalcogenide glass film sample in a sealed environment filled with oxygen-containing gas.

[0010] Preferably, the laser exposure conditions are saturation exposure of the chalcogenide glass thin film sample.

[0011] Preferably, the chemical formula of the Ge-Sb-Se ternary chalcogenide glass is Ge x Sb y Se z (10≤ x ≤35, 5≤ y ≤30,55≤ z ≤85, and x + y + z =100).

[0012] Preferably, the center wavelength of the semiconductor laser is 200-800nm.

[0013] Preferably, the laser power is greater than 0.01W and is sufficient to induce a photoinduced change in the refractive index of the chalcogenide glass.

[0014] Preferably, the exposure time is greater than the threshold time for the chalcogenide glass to reach saturation exposure, and less than the threshold time for the chalcogenide glass to produce a thermal annealing effect.

[0015] Preferably, the threshold time for saturation exposure refers to the shortest exposure time at a fixed laser power when the refractive index of the chalcogenide glass no longer changes significantly when the exposure time is extended further.

[0016] Preferably, the threshold time of the thermal annealing effect refers to the critical time at which, under a fixed laser power, excessive exposure time leads to localized heat accumulation caused by the laser, resulting in a significant change in the refractive index of the chalcogenide glass.

[0017] Preferably, the oxygen-containing gas is oxygen, or oxygen-enriched air with an oxygen volume fraction greater than 50%.

[0018] Compared with the prior art, the present invention achieves the following technical effects: (1) Simple and efficient process: The refractive index change can be significantly enhanced simply by controlling the ambient atmosphere during laser exposure. The process is simple and does not require complex doping or annealing. Specifically, compared with traditional methods such as elemental doping or annealing, it can significantly enhance the refractive index change of chalcogenide glass films simply by controlling the ambient atmosphere during laser exposure, without introducing complex external processing steps. The process relies on conventional equipment such as semiconductor lasers and standard atmosphere devices, which greatly reduces the technical threshold and cost.

[0019] (2) Stable and controllable performance: The refractive index change induced by this process is non-volatile, has good uniformity, and high repeatability, making it suitable for the fabrication of high-precision optical devices such as optical waveguides and micro-nano devices. (3) Good industrialization prospects: The lasers, coating and optical inspection equipment involved in the process are all conventional instruments, which are easy to achieve large-scale production and industrial application. Attached Figure Description

[0020] For ease of explanation, the present invention will be described in detail below with reference to specific embodiments and accompanying drawings.

[0021] Figure 1 This is a schematic diagram of the exposure apparatus for the air atmosphere exposure process proposed in this invention.

[0022] Figure 2 This is a schematic diagram of the exposure apparatus for the oxygen-enriched atmosphere exposure process proposed in this invention.

[0023] Figure 3 This is a comparison of the refractive index curves of a chalcogenide glass thin film sample before and after exposure in an air atmosphere, provided by the present invention.

[0024] Figure 4 This is a comparison of the refractive index curves of a chalcogenide glass thin film sample before and after exposure in an oxygen-rich atmosphere, as provided by the present invention.

[0025] Figure 5 This is a comparison chart showing the change in refractive index of chalcogenide glass thin film samples before and after exposure in air and oxygen-rich atmospheres, as provided by the present invention.

[0026] In the figure: 1. Semiconductor laser; 2. Chalcogenide glass thin film sample; 3. Soda-lime glass substrate; 4. Sealed transparent container. Detailed Implementation

[0027] The following are specific embodiments of the present invention, described in conjunction with the accompanying drawings, to further illustrate the technical solutions of the present invention. However, the present invention is not limited to these embodiments. Specific details, such as particular configurations, are provided in the following description merely to aid in a comprehensive understanding of the embodiments of the present invention. Therefore, those skilled in the art should understand that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present invention.

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other.

[0029] Unless otherwise specified, the materials, practices, and experimental equipment involved in the embodiments of this invention are all commercially available products in the relevant chemical and biotechnology fields.

[0030] Example 1 Ge film with a thickness of approximately 550 nm was prepared on a soda-lime glass substrate using a vacuum thermal evaporation deposition process. 20 Sb 15 Se 65 Chalcogenide glass thin films were deposited at a rate controlled at approximately 3 Å / s. The sample was exposed using a semiconductor laser with a center wavelength of 638 nm. The exposure conditions were: laser power 2 W, spot radius 20 mm, and exposure time 4 h. The exposure environment was as follows: in an air atmosphere, the sample was placed directly in the experimental environment; in an oxygen-enriched atmosphere, the sample was placed in a sealed transparent container, which was evacuated and then filled with oxygen to standard atmospheric pressure to create an oxygen-enriched environment.

[0031] Example 2: The transmission spectrum of the sample before and after exposure was measured using a spectrophotometer. The refractive index in the wavelength range of 600-2400 nm was calculated using the Swanepoel method, and the change in refractive index under different atmospheres was compared.

[0032] like Figure 1 As shown, this is an exposure apparatus for an air-atmosphere exposure process.

[0033] like Figure 2 As shown, in the exposure apparatus of the exposure process under an oxygen-rich atmosphere, the semiconductor laser is turned on, and the position of the chalcogenide glass thin film sample is adjusted so that the center position of the laser beam irradiates the sample for exposure.

[0034] like Figure 3 As shown, the refractive index curves of the chalcogenide glass film samples after exposure in an air atmosphere decrease compared to the refractive index curves before exposure. Specifically, at 808 nm, the refractive index of the chalcogenide glass film sample after exposure is 2.821, while the refractive index before exposure is 2.842; at 980 nm, the refractive index of the chalcogenide glass film sample after exposure is 2.721, while the refractive index before exposure is 2.738; at 1310 nm, the refractive index of the chalcogenide glass film sample after exposure is 2.643, while the refractive index before exposure is 2.657; and at 1550 nm, the refractive index of the chalcogenide glass film sample after exposure is 2.617, while the refractive index before exposure is 2.631. Figure 3 The conclusion is that the refractive index of the chalcogenide glass thin film sample decreases after exposure in an air atmosphere.

[0035] like Figure 4 As shown, it is possible to obtain the same result as... Figure 3Similar trends were observed. The refractive index curves of the chalcogenide glass film samples after exposure in an oxygen-rich atmosphere showed a significant decrease compared to the unexposed curves within the measurement wavelength range. Specifically, at 808 nm, the refractive index of the exposed chalcogenide glass film sample was 2.742, compared to 2.842 before exposure; at 980 nm, the refractive index was 2.644, compared to 2.738 before exposure; at 1310 nm, the refractive index was 2.576, compared to 2.657 before exposure; and at 1550 nm, the refractive index was 2.556, compared to 2.631 before exposure. Figure 4 The conclusion is that exposure in an oxygen-rich atmosphere can effectively change the refractive index of chalcogenide glass films.

[0036] like Figure 5 As shown, the change in refractive index of the chalcogenide glass film sample before and after exposure in an oxygen-enriched atmosphere is significantly greater than that before and after exposure in an air atmosphere. Specifically, at 808 nm, the change in refractive index of the chalcogenide glass film sample before and after exposure in an oxygen-enriched atmosphere is 0.101, while the change in refractive index before and after exposure in an air atmosphere is 0.021; at 980 nm, the change in refractive index of the chalcogenide glass film sample before and after exposure in an oxygen-enriched atmosphere is 0.094, while the change in refractive index before and after exposure in an air atmosphere is significantly greater. The refractive index change of the chalcogenide glass thin film sample before and after exposure in an oxygen-rich atmosphere was 0.017; at 1310 nm, the refractive index change of the chalcogenide glass thin film sample before and after exposure in an oxygen-rich atmosphere was 0.081, and the refractive index change of the chalcogenide glass thin film sample before and after exposure in an air atmosphere was 0.014; at 1550 nm, the refractive index change of the chalcogenide glass thin film sample before and after exposure in an oxygen-rich atmosphere was 0.075, and the refractive index change of the chalcogenide glass thin film sample before and after exposure in an air atmosphere was 0.014. Figure 5 The conclusion is that, in the infrared band, the change in refractive index of the chalcogenide glass film sample before and after exposure in an oxygen-enriched atmosphere is significantly higher than that in an air atmosphere. At 808 nm, the change in refractive index in an oxygen-enriched atmosphere is about 4.8 times that in an air atmosphere, while at other test wavelengths (980 nm, 1310 nm, 1550 nm), it can reach more than 5 times, which proves the effectiveness of the process of the present invention.

[0037] Those skilled in the art to which this application pertains may modify or supplement the specific embodiments described or use similar methods to replace them, but without departing from the inventive concept of this application or exceeding the scope defined by the appended claims.

Claims

1. A laser exposure process for enhancing the refractive index change of chalcogenide glass thin films, characterized in that, Includes the following steps: Preparation of chalcogenide glass thin films on soda-lime glass substrates; Place the film in a preset atmosphere environment; Laser exposure of the thin film using a laser whose wavelength matches the absorption wavelength of the chalcogenide glass film can change the refractive index of the film, and a higher refractive index change can be obtained in an oxygen-rich atmosphere than in an air atmosphere.

2. The process according to claim 1, characterized in that, The chalcogenide glass material is a Ge-Sb-Se ternary structure chalcogenide glass.

3. The process according to claim 1, characterized in that, The chalcogenide glass film was prepared by vacuum deposition technology.

4. The process according to claim 1, characterized in that, The oxygen-rich atmosphere is formed by placing a chalcogenide glass film sample in a sealed environment filled with oxygen-containing gas.

5. The process according to claim 1, characterized in that, The laser exposure conditions are saturation exposure of the chalcogenide glass thin film sample.

6. The process according to claim 2, characterized in that, The chemical formula of the Ge-Sb-Se ternary chalcogenide glass is Ge. x Sb y Se z , where 10≤ x ≤35, 5≤ y ≤30,55≤ z ≤85, and x + y + z =100.

7. The process according to claim 1, characterized in that, The center wavelength of the semiconductor laser is 200-800nm.

8. The process according to claim 1, characterized in that, The laser power is greater than 0.01W and is sufficient to induce a photoinduced change in the refractive index of the chalcogenide glass.

9. The process according to claim 1, characterized in that, The exposure time is greater than the threshold time for saturating exposure of the chalcogenide glass, and less than the threshold time for thermal annealing of the chalcogenide glass.

10. The process according to claim 9, characterized in that, The threshold time for saturation exposure refers to the shortest exposure time at which the refractive index of the chalcogenide glass no longer changes significantly when the exposure time is extended further under a fixed laser power.

11. The process according to claim 9, characterized in that, The threshold time of the thermal annealing effect refers to the critical time at which, under a fixed laser power, excessive exposure time leads to localized heat accumulation caused by the laser, resulting in a significant change in the refractive index of the chalcogenide glass.

12. The process according to claim 4, characterized in that, The oxygen-containing gas is oxygen, or oxygen-enriched air with an oxygen volume fraction greater than 50%.

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